1. Field of the Invention
This invention relates to a pickup to detect an insertion position and orientation of the insertion unit of the endoscope into body to be tested.
2. Description of Related Art
In general, an endoscope apparatus is designed to insert a thin, flexible insertion unit into a part to be inspected in a body cavity and to observe or treat, if necessary, such inspected part. Since the body cavity, such as the small and large intestines, is typically of a winding shape, the position and orientation of the inserted endoscope insertion unit is not readily known to the operator.
Traditionally, an X ray is irradiated to the inspected part with the endoscope insertion unit inserted from outside of the body to check the insertion state, such as insertion position and orientation of the insertion unit in the body cavity.
Such X ray, however, is not completely harmless to the body and restricts irradiation parts, thus not always being suitable as a detection method for insertion state of the endoscope insertion unit.
While a pickup, as set forth in the U.S. Pat. No. 4,176,662, to detect the position of the tip of an endoscope or a catheter to be inserted into body cavities is available at present, the pickup has no capability of detecting the orientation and state of the endoscope inserted in winding body cavity.